Vehicles with conveyers, pumps, cranes, etc., mounted on them must be stabilized during use of the conveyors, pumps, cranes, etc. One approach involves using outriggers, which extend beyond the vehicle's frame and wheels. When not in use, these outriggers must be stowed substantially within the boundaries of the vehicle during road transport.
A system of swing outriggers, which are known in the art, typically includes a pair of front outriggers pivotally mounted near the vehicle's cab on opposite sides of the vehicle. These front outriggers swing forward about a pivot point from their stowed position to a stability position. The outrigger system also typically includes rear outriggers pivotally mounted near a back end of the vehicle on opposite sides of the vehicle. These rear outriggers swing backward about a pivot point from their stowed position to a stability position. The front and rear swing outriggers are pivotally mounted via generally horizontal arms and include a joint from which a leg can be pivotally lowered to contact a firm surface in the stability position.
Powered outriggers are preferred for safety and ease of use because outriggers are heavy and injuries can result when manually deploying and storing the outriggers. In addition, powered mechanisms can ensure full deployment, which is important for safety during operation, and full stowage, which is important for safety during transport. Powered deployment and stowage is also strongly preferred for ease of use.
Top-down perspective views of a prior art powered outrigger system 100 is pictured in FIGS. 1A and 1B, which show both the deployed stability position (FIG. 1A) and the storage position for road transport (FIG. 1B). The system 100 includes four outriggers 102A-D, and each outrigger includes a hydraulic cylinder 104A-D that extends to place the associated outrigger in the stability position and then retracts to place the associated outrigger in the stowed position. The hydraulic cylinders 104A-D are pivotally mounted at one point to a box beam and pivotally mounted at the other end to the arm of a respective outrigger. The arc of the swing of each outrigger is directly proportional to and limited by the stroke of the hydraulic cylinder. In the example of FIGS. 1A and 1B, the swing of the rear outriggers (i.e., 102C and 102D) is limited to about 110 degrees.